Thin film resistors can be used to generate heat. When heated, some of these resistors reach high temperatures (e.g., 400-600xc2x0 Celsius). In some environments, the resistors are temperature cycled repeatedly. During the ramp-up portions of their temperature cycles, the resistors often heat much more quickly than the substrates on which they are deposited, thereby subjecting the resistors to compressive stresses. In a similar fashion, the resistors are subjected to tensile stresses during the ramp-down portions of their temperature cycles (because the resistors often cool much more quickly than the substrates on which they are deposited). These repeated stresses fatigue the resistors, and sometimes cause the resistors to crack.
Additionally, because the thin-film resistor is contacting the substrate, the heating process is not efficient. The heat lost in the substrate may be an order of magnitude higher than the heat generated above the resistor.
A suspended thin-film resistor and methods for producing the same are disclosed. In one embodiment, a device Is produced by depositing a first and second contact on a substrate. A sacrificial material is deposited on the substrate at a location between the first and second contacts. A thin-film resistor is deposited over the first and second contacts and the sacrificial material. Finally, the sacrificial material is thermally decomposed.